ArcGIS – How to Rename Feature Classes Based on Field Values

arcgis-10.0arcpy

My goal is to iterate through several feature classes and rename each feature class based on a field value within the feature class's attribute table. These feature classes are a single polygon feature, thus they only have a single row in the attribute table. I was thinking I could use the Rename GP tool to do this so I've got that part figured out. Next I can use the SearchCursor to find the field value that I want to use to rename the feature class with.

So I'm struggling here in two places. First, I'm unsure how to iterate through each of the feature classes to get their current names and then apply that to the first parameter of the arcpy.Rename_management tool. I know I can get the name of the feature class using arcpy.Describe but I'm stuck after that. Second, I'm struggling with how to assign each of the field values from the attribute table to a variable to be used for the second parameter of the Rename tool. I can easily print the name using rows = arcpy.SearchCursor(fc, "", "", "name") for row in rows: print row.name but I'm struggling with how to assign its value to a variable.

Let me know if I need to explain this any better.

Best Answer

You can try something like this:

import arcpy
import glob

def main():
    for f in glob.glob(r'C:\test\*.shp'):
        rows = arcpy.SearchCursor(f, '', '', 'name')
        for r in rows:
            try:
                arcpy.Rename_management(f, r.name)
            except:
                print 'Error: Unable to rename ' + f + ' to ' + r.name
            break
        del rows

if __name__ == '__main__':
    main()

Related Solutions

[GIS] How to check for empty values in fields of a featureclass

I just wanted to point out that just using if not row.Stand may yield undesired results (remember, explicit is better than implicit from the Zen of Python). Take the following example:

>>> for i, sample in enumerate(['a',1,None, '', ' ', 0]):
    if not sample:
        print 'value "{}" at index {} is empty'.format(sample, i)


value "None" at index 2 is empty
value "" at index 3 is empty
value "0" at index 5 is empty

We can see here that a single space returns true, because it is a character. We are also removing zeros (which may or may not be a "NULL" value, depends on the situation).

Instead, it may be better to test if it is None or if the string contains any non-whitespace characters:

>>> for i, sample in enumerate(['a',1,None, '', ' ', 0]):
    if sample is None or not str(sample).strip():
        print 'value "{}" at index {} is empty'.format(sample, i)


value "None" at index 2 is empty
value "" at index 3 is empty
value " " at index 4 is empty

Now we have removed any values that are just white space. This may not be a big issue, but me having prior work experience in an assessors office, there were plenty of parcel fields that were supposed to have values and only contained white space would not be flagged in the simple if not row.Field example. Here is what you can use to test for a single field:

rows = arcpy.SearchCursor(fc,"","","","")
for row in rows:
   if row.Stand is None or not str(row.Stand).strip():
        print 'empty row!'
        break

Or, if you want to test all fields:

import arcpy
fc = r'C:\TEMP\Huxley.gdb\Watermain\WtrValve'
fields = dict((f.name, []) for f in arcpy.ListFields(fc) if not f.required)

rows = arcpy.SearchCursor(fc,"","","","")
for row in rows:
    for f in fields.keys():
        fields[f].append(row.getValue(f))

for field, values in fields.iteritems():
    if any(map(lambda s: s is None or not str(s).strip(), values)):
        print 'Field: "{}" has empty values'.format(field)

This yielded:

>>> 
Field: "VAL_TYPE" has empty values
Field: "GNSS_HEIGHT" has empty values
Field: "HL_ACCU" has empty values
Field: "PHOTO_1" has empty values
Field: "COMMENTS" has empty values
Field: "PROJ_NUMB" has empty values
Field: "PDF_LOC" has empty values
Field: "YR_INST" has empty values
Field: "TOP_COND" has empty values
Field: "VAL_USE" has empty values
Field: "ASBUILT" has empty values
Field: "PROJ_NAME" has empty values

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